Introduce class for setting up debug integration

jupyter-lib/shared-compiler/src/main/kotlin/org/jetbrains/kotlinx/jupyter/debug/DebugIntegration.kt

@@ -0,0 +1,21 @@
+package org.jetbrains.kotlinx.jupyter.debug
+
+import kotlin.concurrent.thread
+
+abstract class DebugIntegrationProvider(
+    protected val debugPort: Int?,
+) {
+    companion object {
+        const val DEBUG_THREAD_NAME = "NotebookDebugThread"
+    }
+
+    fun provideDebugPort(): Int? = debugPort
+
+    fun provideSuspendedThread(runnable: () -> Unit): Thread {
+        return thread(start = provideDebugPort() != null, name = DEBUG_THREAD_NAME, block = runnable)
+    }
+}
+
+class NotebookDebugIntegrationProvider(
+    debugPort: Int?,
+) : DebugIntegrationProvider(debugPort)

jupyter-lib/shared-compiler/src/main/kotlin/org/jetbrains/kotlinx/jupyter/debug/DebugIntegrationProviderMock.kt

@@ -0,0 +1,3 @@
+package org.jetbrains.kotlinx.jupyter.debug
+
+object DebugIntegrationProviderMock : DebugIntegrationProvider(null)

jupyter-lib/shared-compiler/src/main/kotlin/org/jetbrains/kotlinx/jupyter/repl/creating/DefaultReplComponentsProvider.kt

@@ -3,6 +3,8 @@ package org.jetbrains.kotlinx.jupyter.repl.creating
 import org.jetbrains.kotlinx.jupyter.api.JupyterClientType
 import org.jetbrains.kotlinx.jupyter.api.libraries.CommManager
 import org.jetbrains.kotlinx.jupyter.config.logger
+import org.jetbrains.kotlinx.jupyter.debug.DebugIntegrationProvider
+import org.jetbrains.kotlinx.jupyter.debug.NotebookDebugIntegrationProvider
 import org.jetbrains.kotlinx.jupyter.libraries.LibraryResolver
 import org.jetbrains.kotlinx.jupyter.libraries.ResolutionInfoProvider
 import org.jetbrains.kotlinx.jupyter.messaging.DisplayHandler
@@ -63,8 +65,10 @@ class DefaultReplComponentsProvider(
         return _commManager
     }
 
-    override fun provideDebugPort(): Int? {
-        return _settings.kernelConfig.debugPort
+    override fun provideDebugIntegration(): DebugIntegrationProvider {
+        return NotebookDebugIntegrationProvider(
+            _settings.kernelConfig.debugPort,
+        )
     }
 
     override fun provideExplicitClientType(): JupyterClientType? {

jupyter-lib/shared-compiler/src/main/kotlin/org/jetbrains/kotlinx/jupyter/repl/creating/LazilyConstructibleReplComponentsProvider.kt

@@ -2,6 +2,7 @@ package org.jetbrains.kotlinx.jupyter.repl.creating
 
 import org.jetbrains.kotlinx.jupyter.api.JupyterClientType
 import org.jetbrains.kotlinx.jupyter.api.libraries.CommManager
+import org.jetbrains.kotlinx.jupyter.debug.DebugIntegrationProvider
 import org.jetbrains.kotlinx.jupyter.libraries.LibrariesScanner
 import org.jetbrains.kotlinx.jupyter.libraries.LibraryResolver
 import org.jetbrains.kotlinx.jupyter.libraries.ResolutionInfoProvider
@@ -29,8 +30,10 @@ abstract class LazilyConstructibleReplComponentsProvider : ReplComponentsProvide
     override val homeDir: File? by lazy { provideHomeDir() }
     protected abstract fun provideHomeDir(): File?
 
-    override val debugPort: Int? by lazy { provideDebugPort() }
-    protected abstract fun provideDebugPort(): Int?
+    override val debugPort: Int? by lazy { debugIntegrationProvider.provideDebugPort() }
+
+    override val debugIntegrationProvider: DebugIntegrationProvider by lazy { provideDebugIntegration() }
+    protected abstract fun provideDebugIntegration(): DebugIntegrationProvider
 
     override val mavenRepositories: List<MavenRepositoryCoordinates> by lazy { provideMavenRepositories() }
     protected abstract fun provideMavenRepositories(): List<MavenRepositoryCoordinates>

jupyter-lib/shared-compiler/src/main/kotlin/org/jetbrains/kotlinx/jupyter/repl/creating/ReplComponentsProvider.kt

@@ -2,6 +2,7 @@ package org.jetbrains.kotlinx.jupyter.repl.creating
 
 import org.jetbrains.kotlinx.jupyter.api.JupyterClientType
 import org.jetbrains.kotlinx.jupyter.api.libraries.CommManager
+import org.jetbrains.kotlinx.jupyter.debug.DebugIntegrationProvider
 import org.jetbrains.kotlinx.jupyter.libraries.LibrariesScanner
 import org.jetbrains.kotlinx.jupyter.libraries.LibraryResolver
 import org.jetbrains.kotlinx.jupyter.libraries.ResolutionInfoProvider
@@ -20,6 +21,7 @@ interface ReplComponentsProvider {
     val scriptClasspath: List<File>
     val homeDir: File?
     val debugPort: Int?
+    val debugIntegrationProvider: DebugIntegrationProvider?
     val mavenRepositories: List<MavenRepositoryCoordinates>
     val libraryResolver: LibraryResolver?
     val runtimeProperties: ReplRuntimeProperties

jupyter-lib/shared-compiler/src/main/kotlin/org/jetbrains/kotlinx/jupyter/repl/creating/ReplComponentsProviderBase.kt

@@ -3,6 +3,8 @@ package org.jetbrains.kotlinx.jupyter.repl.creating
 import org.jetbrains.kotlinx.jupyter.api.JupyterClientType
 import org.jetbrains.kotlinx.jupyter.api.libraries.CommManager
 import org.jetbrains.kotlinx.jupyter.config.defaultRuntimeProperties
+import org.jetbrains.kotlinx.jupyter.debug.DebugIntegrationProvider
+import org.jetbrains.kotlinx.jupyter.debug.DebugIntegrationProviderMock
 import org.jetbrains.kotlinx.jupyter.libraries.EmptyResolutionInfoProvider
 import org.jetbrains.kotlinx.jupyter.libraries.LibrariesScanner
 import org.jetbrains.kotlinx.jupyter.libraries.LibraryResolver
@@ -28,6 +30,7 @@ abstract class ReplComponentsProviderBase : LazilyConstructibleReplComponentsPro
         commManager,
         explicitClientType,
         librariesScanner,
+        debugIntegrationProvider,
     )
 
     override fun provideScriptClasspath() = emptyList<File>()
@@ -46,5 +49,5 @@ abstract class ReplComponentsProviderBase : LazilyConstructibleReplComponentsPro
     override fun provideExplicitClientType(): JupyterClientType? = null
 
     override fun provideCommunicationFacility(): JupyterCommunicationFacility = CommunicationFacilityMock
-    override fun provideDebugPort(): Int? = null
+    override fun provideDebugIntegration(): DebugIntegrationProvider = DebugIntegrationProviderMock
 }

jupyter-lib/shared-compiler/src/main/kotlin/org/jetbrains/kotlinx/jupyter/repl/notebook/impl/NotebookImpl.kt

@@ -24,6 +24,7 @@ import org.jetbrains.kotlinx.jupyter.api.libraries.Variable
 import org.jetbrains.kotlinx.jupyter.codegen.FieldsProcessorInternal
 import org.jetbrains.kotlinx.jupyter.codegen.ResultsRenderersProcessor
 import org.jetbrains.kotlinx.jupyter.codegen.TextRenderersProcessorWithPreventingRecursion
+import org.jetbrains.kotlinx.jupyter.debug.DebugIntegrationProvider
 import org.jetbrains.kotlinx.jupyter.libraries.parseLibraryDescriptor
 import org.jetbrains.kotlinx.jupyter.repl.EvalData
 import org.jetbrains.kotlinx.jupyter.repl.ReplRuntimeProperties
@@ -37,7 +38,15 @@ class NotebookImpl(
     override val commManager: CommManager,
     private val explicitClientType: JupyterClientType?,
     override val libraryLoader: LibraryLoader,
+    debugIntegrationProvider: DebugIntegrationProvider,
 ) : MutableNotebook {
+    private fun `$debugMethod`() {
+        while (true) {
+            Thread.sleep(1000)
+        }
+    }
+    private val debugThread = debugIntegrationProvider.provideSuspendedThread(::`$debugMethod`)
+
     private val cells = hashMapOf<Int, MutableCodeCell>()
     override var sharedReplContext: SharedReplContext? = null
 

src/main/kotlin/org/jetbrains/kotlinx/jupyter/repl/creating/creatingUtil.kt

@@ -1,6 +1,8 @@
 package org.jetbrains.kotlinx.jupyter.repl.creating
 
 import org.jetbrains.kotlinx.jupyter.config.defaultRuntimeProperties
+import org.jetbrains.kotlinx.jupyter.debug.DebugIntegrationProvider
+import org.jetbrains.kotlinx.jupyter.debug.NotebookDebugIntegrationProvider
 import org.jetbrains.kotlinx.jupyter.libraries.EmptyResolutionInfoProvider
 import org.jetbrains.kotlinx.jupyter.libraries.LibraryResolver
 import org.jetbrains.kotlinx.jupyter.libraries.ResolutionInfoProvider
@@ -37,7 +39,9 @@ fun createRepl(
         override fun provideIsEmbedded() = isEmbedded
         override fun provideDisplayHandler() = displayHandler
         override fun provideCommunicationFacility(): JupyterCommunicationFacility = communicationFacility
-        override fun provideDebugPort(): Int? = debugPort
+        override fun provideDebugIntegration(): DebugIntegrationProvider {
+            return NotebookDebugIntegrationProvider(debugPort)
+        }
     }
     return componentsProvider.createRepl()
 }

src/test/kotlin/org/jetbrains/kotlinx/jupyter/test/repl/AbstractReplTest.kt

@@ -79,7 +79,6 @@ abstract class AbstractReplTest {
             override fun provideIsEmbedded() = false
             override fun provideDisplayHandler() = displayHandlerProvider(notebook)
             override fun provideCommunicationFacility() = CommunicationFacilityMock
-            override fun provideDebugPort(): Int? = null
         }
         return factory.createRepl()
     }